Common Causes of Watery Eyes in Dogs
As mentioned, there are different possible causes of eye problems in dogs that can result in epiphora. The severity of the condition and the damage it causes can vary depending on the specific cause. Here are a few of the common causes of eye problems in dogs that usually cause excessive eye discharge:
Physical trauma to the eye can result in damage to the cornea, the clear surface of the eye. Depending on the degree of damage, corneal problems can be either a shallow abrasion or deep ulceration. Regardless of the degree of damage, corneal injury almost always results in excessive tear production in dogs.
As a response to the injury, the glands surrounding the eyes will produce discharge more than usual for many reasons: to facilitate healing of the corneal damage, to lubricate the surface of the eye and prevent further corneal injury, and serves as an attempt to rinse off any irritants and contaminants that can cause complications.
Like in humans, dogs can develop infections in their eyes due to bacterial, viral, or fungal organisms. Some eye infections are primary and transmitted either from an infected animal or from the environment, but most eye infections are secondary and occur as a complication to several forms of eye damage.
Eye infections in dogs result in excessive eye discharge which can be clear, yellow, or green, depending on the specific infectious cause. This is often accompanied by redness of the eye and cloudiness of the clear portion of the eye, depending on the severity of the infection.
The eyes and the nasal passages are connected via a very small duct called the nasolacrimal duct. This allows the drainage of tears produced by the eyes through the nose, the reason behind nasal and ocular discharges in certain conditions in dogs. When this duct becomes blocked, drainage of tears becomes compromised resulting in excessive eye discharge in dogs.
Certain conditions not directly related to the eyes can also result in excessive tear production in dogs. The eyelids, which are designed to protect the eyes, can have physical abnormalities that can cause excessive tear production.
One common eyelid problem seen in dogs is entropion. It is described as the inward folding of the eyelids irritating the eye and resulting in excessive tear production. This is usually seen in breeds with high degrees of facial skin folds such as Sharpeis, Bulldogs, and Chow Chows.
Another eyelid problem that results in excessive eye discharge is distichiasis. This is characterized by the growth of eyelashes in locations they do not usually grow. Normally, eyelashes grow at the edge of the upper and lower eyelids and serve to protect the eyes from external hazards. In cases of distichiasis, eyelashes sometimes grow in the inner eyelids and irritate the eye itself, resulting in profusely watery eyes.
Symptoms of Excessive Tearing and Eye Discharge in Dogs
In most cases, its easy to tell if your dogs eyes are too teary or there is an eye discharge. This may be accompanied by other abnormal eye signs.
Diagnosis of Eye Drainage in Dogs
First, your veterinarian will get a history from you, asking questions about lifestyle, past health concerns, and the current signs you have noticed. Next, a veterinary exam will be done. Your veterinarian will examine your dogs eyes with a light.
A “tear test” may be done to check your dogs tear production. This involves placing special paper strips in the eyes and timing how long it takes the tears to reach a line on the paper strip.
Next, a painless, harmless eye dye (called fluorescein stain) may be applied to look for abrasions to the cornea (ulcers). Other eye tests may be recommended depending on the findings of the exam and preliminary tests.